Infectious disease (ID) transmission by way of contact transmission is a significant problem. The most important and frequent mode of transmission of nosocomial infections is by direct contact. Contact transmission may occur either through direct contact with an infected person (direct contact transmission) or may occur by way indirect contact transmission which involves contact of a susceptible host with a contaminated intermediate object that is typically in a public or common area of usage. These contact surfaces are often easily contaminated and may represent vectors for contamination that can lead to the spread of disease through contact transference of contamination.
Light switches, elevator call buttons, elevator panel buttons, security key pads, toilet flush switch buttons are a few examples of contact surfaces that are typical vectors for indirect contact transmission of infectious disease. For example, influenza viruses may be transferred via indirect contact transmission. It is estimated by the US Center for Disease Control (CDC) that influenza viruses affect 5% to 20% of the U.S. population each year. The CDC also estimates that more than 200,000 people a year are hospitalized due to flu complications, and approximately 36,000 die from influenza related infection.
Contamination, such as an influenza virus, transfers indirectly from an infected person or object to another person by way of a contaminated touch surface. Said contamination can enter one's body when hands that have previously touched an infected touch surface also touch the mouth, nose or other area of entry for the contaminant to enter one's body. Other contaminants, that are easily transferred via indirect contact transference include, but are not limited to bacteria such as Methicillin-Resistant Staphylococcus Aureus (MRSA), or Clostridium Difficile (C. dif. or CDF), or the like.
Contact transference of contamination can be especially problematic in hospitals and other care facilities as well as in heavily trafficked public areas such as subway stations or the like. These communal facilities are characterized by numerous contamination vectors, many of which involve indirect contamination transference from one person to another via touch surfaces.
As an example, according to the CDC, approximately 1 out of every 20 hospital patients will experience a hospital acquired infection (HAI) and cost U.S. hospitals as much as $45 B per annually. In 2002 the estimated number of HAIs in U.S. hospitals was estimated to be 1.7 M with nearly 100,000 of these HAIs resulting in death with the average cost per HAI on the order of $25,000 (2002 basis). HAI has become such a significant expense that section 5001(c) of the Deficit Reduction Act states that hospitals will no longer receive reimbursement from CMS for selected conditions related to HAI, adding significant economic burden to numerous U.S. hospitals.
Unfortunately, many of the potential contamination transference vectors characteristic of healthcare facilities and public or common areas are not adequately addressed. It is an object of the present invention to enable the reduction or elimination of transference related contamination from select touch points, including but not limited to electrical switches, and push button switches, such as common light switches, elevator call buttons, elevator panel buttons, toilet flush switches or buttons and the like, in a manner that is efficient, effective and economical.
Electrical or electronic switches (such as light switches, elevator switches, and the like), in common areas such as hotels, typically are contaminated. Said contamination may be transferred from one user of the switch to another at the contact surface of the switch when it is used. This contamination transference vector is thought to contribute to the transfer of myriad communicable diseases. Thus, an effective means of keeping the contact surfaces of switches disinfected is needed.
Manual cleaning of switches is the current state of the art for disinfecting switch contact surfaces. This method requires diligence in order to insure that the entire contact surface of each switch is disinfected. This method is labor intensive, and is therefore costly. It also is typically not consistent and validation tools, such as testing the contact surface after cleaning for microbial substances, are typically not used to verify that cleaning was effective. Additionally, since cleaning is not typically performed after each contact, there is no way to ensure that the surface is disinfected with each contact.
Other methods include use of antiseptic sprays or chemical foggers (e.g., peroxide “bombs” and the like). These methods typically are used to disinfect an entire enclosure and thus, are expensive and must be applied frequently. Additionally, since these disinfection methods are not typically performed after each contact, there is no way to ensure that the surface is disinfected prior to each contact.
Use of UV light has been shown to be effective at killing or passivation of most microbial substances that are known to cause infection or disease. Ultraviolet or UV light is typically divided into three subcategories depending upon the wavelength of the light or electromagnetic radiation comprising the spectrum of said light. These categories are typically known as UV A, UV B or UV C. UV A is generally comprised of wavelengths of electromagnetic radiation mainly in the range of 315 nm to 400 nm, while UV B is generally comprised of wavelengths of electromagnetic radiation mainly in the range of 280 nm to 315 nm and UV C is generally comprised of wavelengths of electromagnetic radiation (EM) mainly in the range of 100 nm or 200 nm to 280 nm. Of these three types of ultraviolet electromagnetic radiation, UV C is generally considered to have the greatest efficacy in killing or in passivating germs that are responsible for disease or infection. For example, germicidal UV radiation of 254 nm wavelength is generally accepted to begin killing or passivating microbes with an exposure of about 2,000 μW-s/cm2 with complete elimination or passivation occurring by exposures in the range of about 12,000 μW-s/cm2. Additionally, wavelengths of EM in the UV C range, especially near and below 100 nm to 200 nm can create ozone that is also an effective germicide. As a result, an effective means of disinfection has been termed UVGI or ultraviolet germicidal irradiation, which uses UV C to effectively kill or passivate surfaces from germs that cause disease or infection.
Unfortunately, UV C also has issues. It is attenuated at a relatively high rate in Earth's atmosphere. It is also harmful to the eyes and skin of humans and animals. Any ozone generated may also be destructive to the lungs of humans or animals. The availability of UV C light sources is also limited and UV C light sources tend to be expensive, relatively inefficient and low powered. Therefore it is important that the UV C source used to disinfect a surface be in close proximity to the surface and that the UV C irradiation be as direct as practicable, and of an appropriate intensity, duration and overall exposure in order to impart sufficient radiation to the surface so as to ensure sufficient sanitization of said surface. It is also important that the UV C radiation be contained enough such that the risk of deleterious exposure to humans or animals is kept to levels that are not significant enough to cause harm to humans or animals. Therefore, it is important to use UV C lights that are of relatively low intensity, that are in close proximity and with suitable angle of incidence to the surface of interest to be decontaminated. It is also important that the UV C source used to sanitize switch contact surfaces be designed to largely contain the UV C radiation so as to minimize UV C exposure of humans and animals to levels that are insignificant.
Several patents that are of interest to the present invention are discussed below. U.S. Pat. Nos. 7,692,172 and 8,097,861, by Leben, teach of a system used to sanitize an enclosed structure using a germicidal ultraviolet light source. The invention sanitizes the entire, human sized enclosure and utilizes at least two sensors, the first to detect the presence or absence of humans or animals within the enclosure and the second to detect the position of the door of the enclosure. The system taught in the patent would be unnecessarily expensive, requiring UV light sources of relatively high intensity, complex electronic logic systems and sensors and only works in the absence of humans or animals, thus not always ensuring a sanitized enclosure when used (e.g., if an elevator is continuously used, the sensors would constantly detect either the presence of humans or animals, or would detect that the door to the enclosure is open or both, and the sanitizing system would not be activated even though the enclosure may be contaminated and need to be sanitized. Additionally, this system is limited in the case of an elevator or the like as it would do nothing to sanitize anything outside the elevator enclosure (e.g., the elevator call buttons or the like).
U.S. Pat. No. 8,143,596 and Published US Patent Application US 2012/0181447, by Yerby, teach of a rigid opaque enclosure open at a door side thereof. An enclosure door is adapted to selectively close the door side of the enclosure. At least one UV bulb is fixed to at least one bulb fixture within the enclosure and extends at least partially into the open internal space of the enclosure. A cage is fixed around each sanitizer bulb. An article fastener is fixed with the cage and is adapted to be selectively fastened to the article for securing the article thereto. An electronic circuit is electrically connected to each sanitizer bulb and is adapted to power each bulb for a present period of time. A switch may be included proximate the door and adapted to electrically close when the door is closed to prevent bulb activation when the door is open. A wheeled support stand may be fixed with the enclosure. The device taught is useful for improving exposure of the article to be sanitized, and thus the sanitizing process especially in the regions of the article where sanitizing is most needed, since the UV light source is in a relatively close proximity to said article and said regions. However, the device described in the patent is rigid and opaque and cannot be used in a manner that allows human or animal access to a contact surface that is inside the volume exposed during the sanitizing process. Thus a switch or other object requiring manual human interaction could not be operated in a normal manner without opening or removing the rigid opaque enclosure from said object thus making it impractical to sanitize the contact surface of said object after each use.
U.S. Pat. No. 7,834,335, and published US Patent Application US 2010/0102252 by Harmon and Douglas teach a convenient mobile sterilization device that provides secure storage in a niche in a protective housing using a one-button action to automatically deploy and activate the sanitizing device for quick and powerful destruction of germs on a surface using one hand. Users can hold the UV-light device and move it across a target surface to sterilize or disinfect the surface. The device may be compact, easily deployed, provided with a durable cover for secure storage, and equipped with safety shut-off features to prevent unwanted uses. The invention taught is useful for sterilization of small objects and is small. However, the device described in the patent completely encloses the object to be sanitized and thus cannot be used in a manner that allows human or animal access to a contact surface that is inside the volume exposed during the sanitizing process. Thus a switch or other object requiring manual human interaction could not be operated in a normal manner without opening or removing the rigid enclosure from said object, thus making it impractical to sanitize the contact surface of said object after each use.
U.S. Pat. No. 6,923,367 by Grossman and Schumann, teaches of a safety mailbox system including a mailbox container integrated with at least one decontaminating mechanism. Contaminants may include chemical and biological agents. The invention taught is useful for sterilization of mail and likely could be modified to effectively disinfect myriad small objects. However, the device described in the patent completely encloses the object to be sanitized and thus cannot be used in a manner that allows human or animal access to a contact surface that is inside the volume exposed during the sanitizing process. Thus a switch or other object requiring manual human interaction could not be operated in a normal manner without opening or removing the rigid enclosure from said object, thus making it impractical to sanitize the contact surface of said object after each use.
U.S. Pat. No. 6,605,260 by Busted, teaches of an apparatus for sterilizing a member that includes a housing, with an enclosure defined therein, a source of ultraviolet light for illuminating the member, and an ozone source. A pump is connected to the ozone source to force the ozone to flow within the enclosure, and a heating device heats the ozone flow. The invention taught is useful for sterilization of myriad small devices. However, the device described in the patent completely encloses the object to be sanitized and thus cannot be used in a manner that allows human or animal access to a contact surface that is inside the volume exposed during the sanitizing process. Thus a switch or other object requiring manual human interaction could not be operated in a normal manner without opening or removing the rigid enclosure from said object, thus making it impractical to sanitize the contact surface of said object after each use.
Published US Patent Application 2011/0291995 by Shr, et al., teaches of a sterilizing device comprising a light guiding member and an ultraviolet (UV) light source. The light guiding member has a surface. The UV light source emits UV light rays such that the UV light rays are guided into the guiding member based on total internal reflection. When an object contacts or comes close to the surface, an evanescent wave from the UV light rays irradiates on the object. This device may be useful for sanitizing a contact surface, but the surface to be sanitized necessarily must be a light guide having total internal reflection. This is impractical in the case of the contact surface of a switch as it would be unnecessarily large and complex and would require replacement of the switch in the case of a retrofitting application. Specialized materials would be necessary as well and the efficacy of this device for sanitizing is unproven. Additionally, the danger of UV exposure to humans or animals by this device is questionable.
Published US Patent Application 2011/0158862, by Kim, et al., teaches of an escalator handrail sterilizer which is installed close to an inlet or outlet of an escalator handrail, and cleans and sterilizes the handrail moving in or out. The sterilizer comprises a case which is prepared for surrounding the escalator handrail, a chemical spray unit which is prepared in one end inside the case to spray chemicals on the handrail moving in, an ultraviolet ray irradiation unit which is prepared in the other end inside the case to project ultraviolet rays on the chemical-sprayed handrail, a drying unit which dries the chemicals sprayed on the handrail, a control unit which controls the chemical spray unit, the UV irradiation unit and the drying unit, and a cover which is prepared in both ends of the case in order to prevent foreign materials from flowing into the case. This device, while highly valuable for sanitizing a moving handrail as used on an escalator, would not be suitable for sanitizing a switch contact surface as it requires that the surface to be sanitized move through the sanitizing unit and it would be impractical to move the switch or the sanitizing unit in this manner between each use of said switch.
Published US Patent Application 2007/0258852, by Hootsmans, et al., teaches of a passenger interface device that includes at least one input member having a contact surface that is adapted to be touched by an individual. A disinfectant is on the contact surface and the disinfectant comprises a radiation-activated material. A source of radiation irradiates the disinfectant to disinfect the contact surface of the passenger interface device. In one example, titanium dioxide is used as a photo-catalyst that disinfects the contact surface responsive to ultraviolet light radiation. This device requires that a permanent disinfectant coating on the contact surface of the switch and that it be irradiated with a light source. One embodiment irradiates the contact surface from behind, requiring the light of suitable intensity to activate the disinfectant. This would necessitate that the light illuminate directly outward from the contact surface which could provide hazardous exposure to humans or animals. Additionally, the disinfectant coating may be impractical to use, requiring switch replacement or difficult and expensive application of the coating that may result in non-satisfactory appearance or functionality. Furthermore, proper use of high energy radiation (UV C or the like) does not require a photo-catalyst or other disinfectant coating in order to sanitize a surface.
Published US Patent Application 2012/0241284, by Kobayashi, et al., teaches of a sterilization and cleaning device of an escalator including a hand rail; a plasma source for irradiating the hand rail with ions or radicals or UV light; and enclosure for housing plasma; a fan for generating relatively negative pressure in the enclosure; filter units for removing removed bacteria, viruses and organic matter such as hand marks; and filter plates located backward and forward of a moving direction of the hand rail in the enclosure along the hand rail. This device is for sanitizing a moving handrail as used on an escalator. As such, it would not be suitable for sanitizing a switch contact surface as it requires that the surface to be sanitized move through the sanitizing unit and it would be impractical to move the switch or the sanitizing unit in this manner between each use of said switch.
Published US Patent Application 2012/0217415, by Wormely, teaches of a device named the “Clean as a Whistle Cleaning System”, which is claimed to be a product that will sanitize and deodorize whistles with the use of a liquid. Accordingly the product accomplishes this goal by the use of unique ultraviolet bulb. The bulb is powered by AA batteries which work in conjunction with the circuit board. The compact and very portable units are equipped with a power button that starts the cleaning process and automatically shuts off the units after the cleaning process has been completed. The process is claimed to take no longer than 15 minutes to complete. In addition, it is claimed that the units are also designed to so additional sanitized whistles. The invention taught is useful for sterilization of whistles and could likely be applied to clean the contact surfaces of myriad small objects. However, the device described in the patent completely encloses the object to be sanitized and thus cannot be used in a manner that allows human or animal access to a contact surface that is inside the volume exposed during the sanitizing process. Thus a switch or other object requiring manual human interaction could not be operated in a normal manner without opening or removing the rigid enclosure from said object, thus making it impractical to sanitize the contact surface of said object after each use.
Published US Patent Application US 2008/0197226, by Cooper and Chen, teaches of a cord reel sanitizer that includes a spool for windingly receiving a cord within a spool housing interior and a sanitizer for sanitizing the spool housing interior. According to one embodiment, the sanitizer includes an ultraviolet lamp generating ultraviolet radiation, most preferably having a wavelength between approximately 250 and 260 nanometers, and a reflector redirecting ultraviolet radiation toward the spool housing interior. A control system for activating the sanitizer may include a manual actuation switch or, alternatively, may sense when a cord is unwound from the spool to activate the sanitizer. The control system may be adapted to activate the sanitizer during a predetermined activation time period. The control system may include a light indicator for visually signaling during activation of the sanitizer. The spool housing may define first and second cord openings for respective passage of first and second ends of a cord to an exterior of the spool housing. The device described in the patent completely encloses the object to be sanitized and thus cannot be used in a manner that allows human or animal access to a contact surface that is inside the volume exposed during the sanitizing process. Thus a switch or other object requiring manual human interaction could not be operated in a normal manner without opening or removing the rigid enclosure from said object, thus making it impractical to sanitize the contact surface of said object after each use. This device would not be suitable for sanitizing a switch contact surface as it requires that the surface to be sanitized move into and out of the sanitizing unit in order to be used and it would be impractical to move the switch or the sanitizing unit in this manner between each use of said switch.
U.S. Pat. No. 8,598,539, by Chuang, teaches of a germicidal device for elevator buttons includes a casing and a lamp tube installed inside the casing and capable of emitting germicidal light. The casing can be fixedly mounted on an elevator control panel for the germicidal light emitted from the lamp tube to project onto all elevator buttons on the elevator control panel, so as to continuously kill any germs on the elevator buttons. The casing is provided on a bottom with an elongated slot, via which the germicidal light emitted from the lamp tube is outward projected onto all the elevator buttons. The lamp tube can be a UV germicidal lamp tube for emitting UV germicidal light. The device taught in the patent has several major drawbacks. The UV light source illuminates from one direction only such that elevator buttons nearest said source receive a much greater level of germicidal UV radiation than the button further from said source. Additionally, the angle of incidence of said UV radiation is extremely low, if not completely horizontal. Thus, the intensity of the light source used would have to be extremely, if not infinitely large. Additionally, this approach will not work if the elevator buttons are flush mounted or recess mounted or the like as the UV radiation will be shielded by the panel. Additionally, anyone using any of the elevator buttons would be exposed to a potentially prohibitive dose of UV radiation as the UV light source would have to be extremely, if not infinitely intense in order to have any germicidal effect upon the elevator buttons at all.
As such, a need exists for an improved sanitizing device for use with a switch or other contact surfaces.